const getDateFn = { //1、 得到今天、昨天、明天日期
  //dates为数字类型，0代表今日,-1代表昨日，1代表明日，返回yyyy-mm-dd格式字符串，dates不传默认代表今日。
  getDate (dates) {
    var dd = new Date(); var n = dates || 0;
    dd.setDate(dd.getDate() + n); var y = dd.getFullYear(); var m = dd.getMonth() +
      1; var d = dd.getDate(); m = m < 10 ? "0" + m : m; d = d < 10 ? "0" + d : d; var
        day = y + "-" + m + "-" + d; return day;
  },
  //2、得到本周、上周、下周的起始、结束日期
  //type为字符串类型，有两种选择，"s"代表开始,"e"代表结束，dates为数字类型，不传或0代表本周，-1代表上
  getMonday (type, dates) {
    var now = new Date(); var nowTime = now.getTime(); var
      day = now.getDay(); var longTime = 24 * 60 * 60 * 1000; var n = longTime * 7 *
        (dates || 0); if (type == "s") { var dd = nowTime - (day - 1) * longTime + n; };
    if (type == "e") { var dd = nowTime + (7 - day) * longTime + n; }; dd = new
      Date(dd); var y = dd.getFullYear(); var m = dd.getMonth() + 1; var d =
        dd.getDate(); m = m < 10 ? "0" + m : m; d = d < 10 ? "0" + d : d; var day = y +
          "-" + m + "-" + d; return day;
  }, //3、得到本月、上月、下月的起始、结束日期
  //type为字符串类型，有两种选择，"s"代表开始,"e"代表结束，months为数字类型，0代表本月，-1代表上月，1代表下月
  getMonth (type, months) {
    var d = new Date(); var year = d.getFullYear(); var
      month = d.getMonth() + 1; if (Math.abs(months) > 12) { months = months % 12; };
    if (months != 0) {
      if (month + months > 12) {
        year++; month = (month + months) %
          12;
      } else if (month + months < 1) { year--; month = 12 + month + months; } else { month = month + months; };
    }; month = month < 10 ? "0" + month : month; var
      date = d.getDate(); var firstday = year + "-" + month + "-" + "01"; var lastday
        = ""; if (month == "01" || month == "03" || month == "05" || month == "07" ||
          month == "08" || month == "10" || month == "12") {
      lastday = year + "-" + month
        + "-" + 31;
    } else if (month == "02") {
      if ((year % 4 == 0 && year % 100 != 0)
        || (year % 100 == 0 && year % 400 == 0)) {
        lastday = year + "-" + month + "-" +
          29;
      } else { lastday = year + "-" + month + "-" + 28; };
    } else {
      lastday = year
        + "-" + month + "-" + 30;
    }; var day = ""; if (type == "s") { day = firstday; }
    else { day = lastday; }; return day;
  },
  //4、得到今年、去年、明年的开始、结束日期
  //type为字符串类型，有两种选择，"s"代表开始,"e"代表结束，dates为数字类型，不传或0代表今年，-1代表去年，1代表明年
  getYear (type, dates) {
    var dd = new Date(); var n = dates || 0; var year =
      dd.getFullYear() + Number(n); if (type == "s") { var day = year + "-01-01"; };
    if (type == "e") { var day = year + "-12-31"; }; if (!type) {
      var day = year +
        "-01-01/" + year + "-12-31";
    }; return day;
  },
}

export default getDateFn;
